Glycopyrronium bromide, formoterol fumarate dihydrate and their related compounds with UPLC/PDA-MS for simultaneous determination in pressurized metered-dose inhaler product.

An ultra-performance liquid chromatography (UPLC) technique with photodiode array-mass spectrometry (PDA-MS) detectors has been developed and validated for the determination of glycopyrronium bromide (GB), formoterol fumarate dihydrate (FFD) and their related substances in pressurized meter dose inhalers. This marks the first time the method has been implemented. Chromatographic analyses have been carried out on a UPLC system with a single quadrupole mass spectrometer (QDa) and a PDA detector. A C18 column has been used prior to the injection valve. The column temperature was set to 40°C. For each analysis, 1 μL of sample was injected at a flow rate of 0.1 mL/minute. The mobile phases used were A (0.5% formic acid in methanol) and B (0.5% formic acid in water). The total run time of the method was 30 minutes. The PDA detector was employed at 215 nm while the mass detector was set to extracted ion chromatography (XIC) mode. The range for detecting impurities of GB was found to be between 0.28 and 0.30 ng/mL, with a limits of 0.92-1.01 ng/mL for quantification. GB and FFD demonstrated linear accuracy. We studied the accuracy of related substances within the limit of quantification value range of corresponding impurities and up to 400% of the limit value. The method we used was linear, rapid, reproducible and accurate. Our proposed method is fast, linear, accurate and reproducible. The UPLC-MS method, which utilized QDa with XIC mode, was developed to ascertain the related substances and assay of GB and FFD.